Microwave assisted extraction of non-volatiles from ginger using ionic liquids

Abstract

Conditions were optimised for the extraction of non-volatiles from ginger using ionic liquids employing microwave energy. Maximum extraction could be achieved with the ionic liquid namely [BMIM]Cl (1-methyl-3-imidazolium chloride) at the concentration of 0.3 M with material to solvent ratio at 1:6 employing the microwave power of 600W, time (5 min.) and temperature (70°C). Microwave assisted extraction using ionic liquid was compared with that of traditional methods with respect to yield and total polyphenolic content (TPP) as well as radical scavenging activity (RSA). Increase in gingerol content (30%) was observed in microwave assisted ionic liquid based extraction than in the conventional extraction. Yield of extract increased by 3.5 fold with optimized condition than the traditional method. Optimized method for the extraction of ginger gives 38.25% increase in the RSA value and 71.93% increase in TPP content compared to the traditional method. The gingerol content released into extract increased by 4.5 folds under optimized condition than the traditional method. It is concluded that microwave assisted ionic liquid extraction can be adopted for the extraction of non-volatiles from ginger and can be extended to the industrial scale also.